Standardization of the homogeneous mobility shift assay protocol for evaluation of anti-infliximab antibodies. Application of the method to Crohn's disease patients treated with infliximab.

BACKGROUND: The availability of a quantitative method to measure anti-infliximab (IFX) antibodies (ATI) would facilitate the implementation of therapeutic drug monitoring in clinical decision-making. Our aim was to standardize the homogeneous mobility shift assay (HMSA) used in the measure of ATI levels. METHODS: In this prospective longitudinal multicenter study, 50 IFX-treated Crohn's disease (CD) patients were followed up for 54weeks. During this period 360 human serum samples were analysed. Monomeric ATI levels were measured by a quantitative HMSA-method using an anti-IFX calibrator. IFX trough levels measured by ELISA were correlated with ATI levels. RESULTS: Using HMSA and a pure anti-idiotypic monoclonal antibody specific for IFX (anti-IFX calibrator), we measured the levels of monomeric ATI generated in Crohn's disease patients treated with IFX. Anti-IFX calibrator allowed to quantify monomeric antibodies against IFX with a low limit of quantification (3nM). The threshold level of ATI in order to classify the immunogenicity of the patients was 10nM. We observed that 24% (12/50) of IFX-treated patients developed ATI (>10nM) during the observation period (54weeks). Serum concentration of ATI higher than 10nM dramatically increased the probability (OR=51.1; 95% CI: 20.4-128.0; p<0.0001) of presenting low levels of IFX (⩽1.5nM) in serum, as observed in some CD patients treated with standard doses of the drug. CONCLUSIONS: The HMSA-method described here allows an accurate quantification of ATI concentration in international units (IU) and therefore it could be useful in the study of the relationship between ATI concentration, infliximab level and the clinical response to the drug.

Disease severity in familial cases of IBD.

BACKGROUND: Phenotypic traits of familial IBD relative to sporadic cases are controversial, probably related to limited statistical power of published evidence. AIM: To know if there are phenotype differences between familial and sporadic IBD, evaluating the prospective Spanish registry (ENEIDA) with 11,983 cases. METHODS: 5783 patients (48.3%) had ulcerative colitis (UC) and 6200 (51.7%) Crohn's disease (CD). Cases with one or more 1st, 2nd or 3rd degree relatives affected by UC/CD were defined as familial case. RESULTS: In UC and CD, familial cases compared with sporadic cases had an earlier disease onset (UC: 33 years [IQR 25-44] vs 37 years [IQR 27-49]; p<0.0001); (CD: 27 years [IQR 21-35] vs 29 years [IQR 22-40]; p<0.0001), higher prevalence of extraintestinal immune-related manifestations (EIMs) (UC: 17.2% vs 14%; p=0.04); (CD: 30.1% vs 23.6%; p<0.0001). Familial CD had higher percentage of ileocolic location (42.7% vs 51.8%; p=0.0001), penetrating behavior (21% vs 17.6%; p=0.01) and perianal disease (32% vs 27.1%; p=0.003). Differences are not influenced by degree of consanguinity. CONCLUSION: When a sufficiently powered cohort is evaluated, familial aggregation in IBD is associated to an earlier disease onset, more EIMs and more severe phenotype in CD. This feature should be taken into account at establishing predictors of disease course.

Smoking does influence disease behaviour and impacts the need for therapy in Crohn's disease in the biologic era.

BACKGROUND: Recently, the notion that smoking may adversely affect Crohn's disease (CD) outcomes has been challenged by the suggestion that the widespread use of immunosuppressants and anti-TNF drugs might offset the adverse effects of tobacco. AIM: To reassess the influence of tobacco smoking on disease phenotype and complications on a time-dependent analysis, taking into account the different therapeutic interventions. METHODS: We designed a retrospective cohort study of 3224 patients with Crohn's disease. The data were collected from the Spanish national inflammatory bowel disease registry (ENEIDA), including information regarding demographics, clinical characteristics, disease complications, therapeutic interventions and smoking status. Patients were classified as nonsmokers, smokers and former smokers, according to their present and past smoking habits. RESULTS: In the univariate analysis, smokers had more strictures (22.6% vs. 19.3%, P < 0.05) and less colonic involvement (7.2% vs. 10.9%, P < 0.05), and were more frequently under treatment with steroids (91.6% vs. 85.8%, P < 0.05), immunosuppressants (73.5% vs. 63.6% P < 0.05) or anti-TNF drugs (31.4% vs. 25.1%, P < 0.05) than nonsmokers. In the time-dependent multivariate analysis, smokers were found to have a significantly decreased survival free of stricturing disease (HR: 1.5, CI 95% 1.18-1.90) or perianal complications (HR: 1.50, CI 95% 1.01-1.46), and had a higher risk for requiring thiopurine therapy (HR: 1.20, CI 95% 1.05-1.30). CONCLUSION: These results suggest that, despite the widespread use of immunosuppressants and anti-TNF drugs, smokers with Crohn's disease still have a more severe disease course, with increased therapeutic requirements when compared with nonsmokers.

Long-term durability of response to adalimumab in Crohn's disease.

BACKGROUND: Adalimumab is an effective treatment for Crohn's disease (CD), but may also be associated with loss of response. Few reports provide insight into the durability of treatment of CD with adalimumab for periods longer than 12 months in clinical practice. AIMS: To evaluate the long-term durability of adalimumab maintenance treatment and to identify predictive factors associated with loss of response. METHODS: CD patients who initially responded to adalimumab were evaluated in a historical cohort study. Maintenance of long-term response was estimated using Kaplan-Meier analysis. Cox regression analysis was performed to identify potential predictive factors for loss of efficacy. RESULTS: In all, 380 CD patients were included (mean age, 38 years; 52% female). Of these, 43% had ileocolic CD, 50% inflammatory CD, and 41% perianal CD. Median follow-up with adalimumab was 8 months (range, 4-75 months). The annual risk of loss of response to adalimumab was 18% per patient-year of follow-up. Twenty-eight percent of patients were anti-TNF-naïve and 72% anti-TNF-experienced. The loss of efficacy was 8% per patient-year of follow-up in the anti-TNF-naïve patients and 22% in the anti-TNF-experienced group (P < 0.01). In the multivariate analysis, the presence of extraintestinal manifestations (hazard ratio [HR] = 1.7; 95% confidence interval [CI] = 1.02-2.9) and previous experience with other anti-TNF agents (HR = 2.5,95% CI = 1.2-5.3) were associated with higher risk of loss of efficacy. CONCLUSIONS: A relevant proportion of CD patients on long-term adalimumab lost response. The risk of loss of response was higher (more than 2-fold) in anti-TNF-experienced than in anti-TNF-naïve patients (22% vs. 8% per patient-year of treatment). Having extraintestinal manifestations seems to increase the risk of loss of efficacy.

Efficacy and safety of short-term adalimumab treatment in patients with active Crohn's disease who lost response or showed intolerance to infliximab: a prospective, open-label, multicentre trial.

BACKGROUND: The use of tumour necrosis factor antagonists has changed the therapeutic approach to Crohn's disease. AIM: To determine response and remission rates associated with the 4-week induction phase of adalimumab treatment in patients with luminal and/or fistulizing Crohn's disease, who have lost response to or become intolerant of infliximab. METHODS: In this multicentre, prospective, open-label, observational, 52-week study, 50 adults received an induction dose of adalimumab (160 mg at baseline followed by 80 mg at week 2). RESULTS: Of the 36 patients with luminal Crohn's disease, 83% achieved clinical response [> or =70-point reduction in the Crohn's Disease Activity Index (CDAI) score] and 42% achieved clinical remission (CDAI score <150) at week 4. Of the 22 patients with fistulizing disease, five (23%) experienced fistula remission (complete closure of all fistulas that were draining at baseline), and nine (41%) experienced fistula improvement (> or =50% decrease in the number of fistulas that were draining at baseline) at week 4. Of the 19 adverse events, most [13 (68%)] were mild, and no serious or infectious adverse events occurred. CONCLUSIONS: Adalimumab may be an effective alternative in patients with luminal and/or fistulizing Crohn's disease who have lost response to or become intolerant of infliximab.

The rendezvous technique for the treatment of choledocholithiasis.

BACKGROUND: The rendezvous technique combines endoscopy with percutaneous transhepatic cholangiography to facilitate cannulation of the bile duct when previous attempts have failed. METHODS: Over a 7-year period, a total of 1753 ERCPs were performed. Twelve of these patients with a diagnosis of choledocholithiasis were poor candidates for surgery. Percutaneous transhepatic cholangiography as well as ERCP with precut papillotomy failed to resolve biliary obstruction. In a further 2 cases the percutaneous approach was used by means of a T-tube positioned at a prior cholecystectomy. OBSERVATIONS: The combined procedure was successful in 13 patients (93%). It was unsuccessful in 1 patient because of a stone lodged distally near the papilla. There was only 1 complication (7%), a retroperitoneal perforation that occurred during papillotomy; no mortality was directly attributable to the technique. CONCLUSIONS: The rendezvous technique is recommended for patients who are not eligible for surgery when ERCP is unsuccessful and when it is impossible to resolve biliary obstruction by percutaneous transhepatic cholangiography.